Fifth wheel for trailers



2 Sheets-Sheet 2 C. M. HARRIS Filed July 26, 1934 FIFTH WHEEL FOR TRAILERS vexfi v; I (Mark; N. H vis -MMQ Afl'ome g Nov. 20, 1934.

\ 20 vantage.

Patented Nov.1 2o,1934

UNITED STATES PATENT OFFl'CE FIFTH WHEEL FOR mamas-s Charles'M. Harris, Holland, inch. Application July 26, 1934, Serial No. 737,038

' 6 Claims. (o1. 280-331) This invention relates generally to coupling devices and more particularly to a'fiIth-wheel construction as is applied betwggn a tractor and a trailer.

Devices of this character have beensomewhat deficient due to their multiplicity of parts whereby they oftentimes getout of order and cause or permit disengagement with serious consequence, as will be understood by those skilled in this art.

In my improved device I eliminate many parts and especially is this true as regards the actual locking mechanism inasmuch as I utilize only a single jaw member. This locking or jaw memher is swingable across the slot into which 'the pin slides and a rocking plunger slides in front of the free end of this locking bar. r

The plunger just mentioned is flanked by an abutment member and this provides another ad- Tiiis advantage is that this integrally formed abutment member is in direct line with the force tending to pull the swingable locking bar to an open position and thus all of the strain caused by this tendency is taken by the abutment. Therefore, there is no danger that an accidental release of the several parts will be had.

Another advantage resides in the automatig I release of the lateral moving plunger'whereby the swingable locking jaw is held in an operative position, this release being had by movement of the pin to its inner or operative position.

Other advantages will be apparent as the ,description proceeds. In the drawings:

, Fig. l is an underplan view of my improved construction. I

' Fig. 2 is a sectional view through Fig. 1, taken along the line 2-2. Fig. 3 is another underplan view, similar to Fig. 1, but the several parts are shown in opened or unlocked position, whereas Fig. 1 shows them in operative or connected position.

Fig. 4 is a sectional view takerfalong the line 454-4ofFig.l.'

Fig. 5 is a fragmentary sectional view showing the trip means before it is actuated, and.

Fig. 6=is a similar view to that shown in Fig. 5 but shows the trip means just after it has been actuated.

Like numerals refer to like parts throughout the several views.

Referring to the drawings, numeral 10 indicates a body plate 1 which has the usual flat top 11 and a throat 12 communicates with the slot 13 whereby the pin 14 is guided to its seat. The pin 14 is attached to the trailer member as indicated at 15, see Fig. 4. The body late 10 has a plurality of ribs 16 whereby the same is strengthened and is pivotally connected asindicated at 1'1 onto the brackets 18 as is shown in Figs. 1 .and 4. Thus the body plate 10 is tiltably mounted.

The ribs 16 are continued inwardly as shown and merge into walls 20 whereby the chamber 21 is formed alongside of the slot 13. A pin 22 extends through the body plate 10 and provides a pivotal mounting for a locking jaw 23. This locking jaw has teeth 24.

, A plunger member 25 has an enlarged front portion 26 and teeth 27 along one side thereof, theseteeth engaging the teeth 24, see Fig. 1, and

this plunger is slidably mounted on the rear wall 9 of the slot and a collar 28 as is clearly shown in Figs. 1, 3 and 4. A spring 29 encircles the plunger between the collar 28 and the enlarged portion 26 and urges the same inwardly at all, times. 1

A second plunger member 40 has an enlarged 'end 41 and is slidably mounted in the side wall 30 of the slot and a collar member 42. The enlarged end 41 engages against an abutment 43,, see Figs. 1 and 3, and it is to be noted that the. enlarged end 41 never extends beyond this abutment member. The opposite side of the enlarged 5 end 41 is slightly beveled as indicated at 44-and this surface cams against the surface 45 of the locked jaw 23 to firmly hold the same in position against the shoulder 46.,

A spring 4'7 surrounds the plunger 40 between 9 the collar 42 and the enlarged end 4I-and urges it inwardly at all times. 0

A lever 50, pivoted at 51, having a handle member 52 has a ball shaped end 53 which seats in a.

recess 54 in the plunger 40 and movement of this lever will cause operation of the plunger. A bev-. eled extension 55 extends from an intermediate portion of the lever. 2 The lever 50 extends through a slot 56 which has a depressed portion 57 at one .end and the latch 58 at its other end. See Fig. '7.

Figs. 5 and 6 indicate the trip mechanism. This mechanism consists of an irregularly shaped member 60 which is fastened to the underside of the bottom plate 10 by means of the bolt and spring connection 61. An extension 62 on this member 60 is adapted to be engaged by the plunger 25. A contacting portion 63 is daptedto ride underneath t e extension 55, on he lever 50, and

raises the le er out of the depressed portion-5'7 as will be later described.

The operation Fig. 1 shows the several elements in locked position. This is the position whenever the trailer 1 is being pulled by the tractor or the like. When the destination has been reached and release of the several parts is desired, the latch member 58 2 is manually raised and the handle member 52 is grasped and this lever is turned about its pivot 51 until itreaches the dotted lineposition shown in Fig. 6 whereupon it is pushed downwardly into the depression 57. This movement is a clockwise movement, referring to Fig. 1, and thus the spring 47 is compressed as the plunger 40 is withdrawn and the enlarged end thereof moves to the position shown in Fig. 3.

The locking jaw 23 is now free to move about the pivot 22 except that the teeth 24 are in engagement with the teeth 27. However, when the pin 14 is drawn forwardly the spring 29 urges the plunger member in the same direction and thus the locking bar 23 will swing to the position shown in Fig. 3. The disengagement is now completed.

It is to be noted that movement of the lever 50, from the position shown in Fig. 1 to that shown in Fig. 3, causes juxtapositioning between the portion 55 thereof and the portion 63 of the irregularly shaped member 60. This is clearly shown in Fig. 5 of the drawings, the dotted lines repre- 'senting the lever member.

Fig. 3 shows the several parts ready for the reception of the pin 1,4 When the pin 14 is moved into the throat 12 and then into the slot 13 it engages aEainst the enlarged end 26 and moves the same inwardly causing the jaw 23, due to the engagement of the gear teeth 24 and 27, to swing against the shoulder 46 and as this occurs the other end of the plunger 25 hits against the projection 62 and turns the member 60 about its universal mounting 61 and causes camming' action between the portion 63 and the extension 55 and this raises the lever 50 out of the depressed portion 57 of the slot 56 to the dotted line position shown in "Fig. 7. In this position, the spring 47 turns the lever as dicated by the arrow in Fig. 7 and the enlarg end 41 of the plunger 40 slides to the position shown in Fig. 1. The portion 44 engages against the portion 45 of the locking jaw 23. The

latch 58 gravitates' or is manuallyturned downwardly whereupon the lever is positively held in its locked position. Also the spring 47 likewise tends to maintain the parts in locked position.

From the above description it will beappreciated that I have invented a coupling device which is easily. actuated but yet which will be positively actuated and thus there is no danger of the driver losing his load. Moreover, only a single jaw is necessary and this jaw is held against accidental opening by an integrally formed abutment whichis capable of t g the heavy strains encountered in mecha isms of this character.

I claim: I

1. A fifth wheel for trailers or the like comprising a body plate having a slotand a throat communicating with each other, a plunger having one end located in the closed end of the slot, said end being recessed, means for slidably mounting the plunger in the body plate, a locking jaw pivotally mounted at one end in the body plate adacent the recessed end of the plunger, said locking jaw being adapted to swing either alongside of or across the slot, interengaging means on the plunger and jaw whereby movement of the plunger causes movement of the jaw, spring means for normally engaging the plunger to urge it forwardly in the slot whereby the locking jaw is shifted to a-position alongside of the slot, an abutment located alongside of the 'slot at the side opposite to that at which the locking jaw is pivoted,

means slidable between the free end of the locking jaw when it is located across the slot and the abutment whereby the spring means causes tight contact therebetween, and apin adapted to slide into the said throat and slot and into the recess of the plunger for the purpose described. 2. A fifth wheel as set forth in claim 1 but also having lever means for operating the last mentioned means and additional means for maintaining the lever in a chosen one of a plurality of positions.

3. A fifth wheel as set forth in claim 1 but also I having lever means for operating the last mentioned means, means for locking the lever means in one position and means associated with the lever locking means and the plunger which is mounted in the body plate whereby movement of the plunger releases the lever locking means.

4. In combination, a body plate having an open ended slotadapted to receive a pin therein, a lever pivoted adjacent the slot and swingable thereacross, plunger means located in the slot and connected to the lever whereby the pin engages the same and moves the lever across the slot, a second plunger mounted upon the body plate, spring means for urging the'plunger to a position in front of the free end of the lever when the lever is, located across the slot. I

5; A combination of elements as recited in claim 4 but which also has means for locking the second plunger in retracted position and means for releasing said second plunger, said means being 10- cated in the path of the plunger means whereby it is operated.

body plate having a slot, a pin slidable thereinto, a locking bar swingable across the slot, a first plunger slidable at right angles to the longitudinal axis of the slot and movable in front of the free end of the locking bar, an abutment located alongside of the said first plunger at the opposite sidewith respect to the locking bar, said abutment extending outwardly a suflicient distance whereby the said firstplunger never extends beyond the same, a spring pressed second plunger engaged by the inward movement of the pin, a spring for urging the first mentioned plunger to operative position, and means actuated by movement of the first mentioned plunger for releasing the spring of the second plunger.

' CHARLES M. HARRIS. 

